That was an interesting problem. Infact database was UP in READONLY mode, what the DBA did, just brought it down. When he re-started (sql> startup;) the database started throwing ORA-00600 error and instance terminated by SMON.ORA-00600: internal error code, arguments: [2662], [1696], [1478225386], [1696], [1956780490], [8388610], [], []

That was very interesting why a re-start caused an ORA-00600 and SMON terminated the instance.

We search through Metalink for this specific ORa-00600 error and found the first argument [2662] points a SCN mismatch, or block corruption etc. But, since the [b] and [d] are same, shows there is no SCN mismatch.

we tried to open the database in READ ONLY mode, and failed with database need recovery.

The DBA knows the database was built reccently from a hot backup and he just tried his luck – just because it was using a backup control file during the recovery. So when the database asked for a recovery he just recoverd using the BACKUP CONTROLFILE.

Interesting, database got opened in READ ONLY mode with out any issues. Then we understood the the original restore did a recovery using BACKUP CONTTROLFILE and open in READ ONLY mode. and never opened in RESETLOGS. So, after restarting the database, got messed up.. There you go..

He again opened the database in RESETLOGS and the database opened normally